Can ML/AI understand incomplete constructs like humans?
I believe that an AI can understand much more of a movie than we do. As you said, sometimes a detail at the beginning of the movie is the key to understanding the final outcome. The problem is that the storyline distracts us. In the case of an AI, he would just be waiting for the movie to complete because he has all the details at all times.

Imagine that an AI is by your side watching the movie. He will not feel emotion like you. He is only analyzing the images, colors, soundtrack, main characters and is extracting from the lines, whatever he can, to understand the movie. What would it be to understand, in your eyes? To be able to generate a synopsis or to compare the film with some reality or criticizes the life of the human?

An artificial superintelligence would have the task of overcoming us. We could pass a movie and let her explain why we cried watching the movie, because we were surprised, and everything. Since an artificial superintelligence would have the role of not being distracted by the film but analyzing all possible content, try to analyze human reactions and spit out an analysis that could leave you reflecting on life for a few days.

But this is an artificial superintelligence that I imagine may one day exist, but I believe it is far away.

Something real and what we can build is an AI that can extract the genre from the movie and maybe even generate a synopsis with a spoiler like "X character dies."

Another factor that also makes it easier for us to understand movies is our huge film base. We watch so many American cliches movies, that most are already very predictable: "The main character does not usually die," "When the villain is close to killing the main character, something surprising happens and he is prevented," ...